1. Field of the Invention
The present invention relates to an automatic gain control (AGC) circuit used in a spread spectrum receiver, a despreading circuit having such an AGC circuit, and a method for reproducing reception data.
2. Description of the Related Art
A spread spectrum scheme is known as a communication scheme having high resistance to noise and interference. Spread spectrum receivers include an automatic gain control (AGC) circuit that controls the signal levels of input signals to correlators, with respect to varying reception levels.
For example, Patent Literature 1 (Japanese Patent Application Laid-Open No. H11-088232) discloses an automatic gain control (AGC) circuit and a spread spectrum receiver that can retrieve n-bit data from m-bit data (m>n) output from a correlator, on the basis of an effective number of bits, in order to reduce the bit width of a demodulator. Patent Literature 2 (Japanese Patent Application Laid-Open No. 2009-232235) discloses an automatic gain control (AGC) circuit in which the higher frequency the signal level of a modulation signal is clipped at, the more highly an amplification factor of an amplifier circuit is corrected.